Headlight tester



July 22, 1952 HEADLIGHT TESTER 3 Sheets-Sheet 14 Filed Oct. 28, 1949 4|/' I I I I I l l lu/ennans.' en?? rmann Raymond LS1/.Kinase July 22, 1952 H. E. HERMANN ErAx. 2,604,003

HEADLIGHT TESTER Filed oct. 28, 1949 5 sheetS-sheet 2 3 Sheets-Sheet 3 H. E. HERMANN Erm.

HEADLIGHT TESTER July 22, 1952 Filed oct. 28, 1949 Patented July 22, 1952 al i :UNIT-ED t STAT-Es PATEN'rvroI-FICE ,y

A f 2,604,003? Y l Y Y' `1411A,DLIGH'T TESTER ,A Henry E. Hermann, Moline,"'andRaymndi-S. "Krause, Rocklsland, Ill.-,`*'assignor's-15d-Bearl Aanufacturing' Comparini-Rock;Island,-Ill., a

corporation of Delaware Q Ar'lplieationr October 28, 1949, Serial" No. 124,122

'z claims. (o1. lss-14).-

automobile 'headlight' testing device and refers particularly to aheadlight testing device by'which the-axis Aof greatest intensity of a beam from a Referring in Adetail to ,the drawings;- I 'indicates generally' a headlight testerconiprisngf-'tlie @features ofour invention. Ther-headlight-testerilv comprises a tubular l"iner'nfber of-4s1ibstanti`a-lly headlight underv test maybe simultaneously lo- 5 square f'cross section having'. bottom lfvvall 2-,1'='top cated electrically by a maximum reading upon an Wall3 andsidewalls yIl and 5. The Walls2-5="niay electric meter and visually upon a Ycalibrated be constructed of any suitable inaterial,prefer screen; ably sheeti'material." vAt the -forwar'd end `Aof-the L' Headlight testers` have Aheretofore been'proheadlighttester l a -framel is`v positionedvsald posedorjocusing the beam'of a headlight under 10 frameibeingadapted to' retain a-'plano-convex 'depending upon visual L'observation' ofthe position ofthe most intensive portion ofthe beam or hot spot," upon thescreen the headlight may be' adjustedtof'properly orient V'the hot spot'upon the "serfeen', Y Y o Y ",1lnso'locatingthehot spot'upon the screen visualj-appraisal of the most intensely illuminated areaof the screen was necessary.A The possibility "oi er'rfoiin thisl regard is apparent since -identi- Acation of the mostf'intenselyilluminatedarea of the screen' is alwaysjsubject tj'o the humanjequation.;l

iight sensitive devices such' as vphotoelectric c'llsj have' heretofore {beenf employed in testing headlights, but said devices were'principally used level l0 which 'may be 'employed in orientinglthe to' determine' quantitatively the .illuminating power oi'thefhe'adlight in'candlepoWeLlumens, or rother;arbitrarily conceived units. V

"Ino1rinvention; thea'rea bi greatest intensity r'ffhotspotrmaybe 'simultaneously appraised as the'hot spot-and' located vuponJ ealibratedf'screen, the" 'appraisal beingaccomplished {electricallyand fvvithoutappreciableerror, 4' Y `-Other objects and advantages of our invention `Wil1` ingsand," fbllovvingv` 'detailed description. y

In thedrawings, Fig. lY is a top'eplanf View; parts ibeingbi'o'k'err'avvayfand'parts being shown irl-sectest .Vupon a calibrated translucent screen land :"5" lens'l.="At`the' rear portion of`the"-he'adli-ght andthe'deviefmaybelpositionedv'a.'predetermined distance avvaylfrom the ln'soia headligii-t't'o be tested,"the` optcalraxis off'lthe-v lens -'I beingf dis-` posed "alongthe foptical' axis of'theheadlight lens. The headlight-'tester l l'carries iat one side'al spirit headlight tester :With-respect to 'the headlight v to be tested.1" In* addition;- an aligning device Iv Il may f be employed in' properly -or'ie'nting th'e' vheadlight tester with' the headlight to be tested, 'theffa'ligning device"being'carriedl upon 'afrod I-2 which -lis adj ust'a'bly' lpcasitioned in sleeve'v l-3 'carried atfthe top of the headlight tester.

'The structural features pir-the' device -flhereini apparent A'from the.' accompanying 'dfrawffl before described: 'are vcove'entimfiallf'andf'per sei' do nct'constitute.l any party fof-@our fpresentf invention exceptvin' Tcmbination-iwith the =elementsfiwhich vvill be hereihafterfmoreilly :described: 1

Inutilizing a` headlight tester fs'uchashasi-ben 'hereinbeforezdescribed after-1the device haslbeen .aligned-properly with. the headlight..tofbef2testedg the headlight? bulb' is f illuminatedf arid 'tl'iel rays projected by-'the headlight pass-'througwthe lens 'l and in the construction'ofwlieadlightitesters '-a'ltrarisve'rse seetionai'rview' taken. ion

v prpiari-fviewoff niouihcationpf eadlight'f"tester.i f

etio'nal Viewv taken on oi t dsli'editheflmobu maybe-rotated Wherebythe y locates the depressed position of the most intense portion of the beam, namely the hot spot of the beam.

As has been hereinbefore described, the beam is focused substantially in the plane of the trans'- lucent screen $1 and in employing, headlight testers heretofore the position of the hot spot of the beam was visually located upon the screen 9 With reference tothe various index lines I4, I5, I1 and the calibrations I6. If the hot spot of the beam were appreciably remote from the line I1 proper adjustment of the headligntwas morder.v However, to locate properly thehot spot, a visual appraisal of what area constitutes jthe hotspot has heretofore been necessary. It can readily be seen that the human equation enters intothis factor and is a source of error.

Asa feature of our invention a frame' I8 is `carried within the body of the headlight tester,

said frame being normally disposed adjacent and in planeparallel relationship with the translucent screen 9. The frame I8 is carried by a rodI9 which is journalled inthe lower portion of theV headlight, tester body. The upper portion of the rod I9 is loosely embraced by a tubular member 20,1said tubular member being journalled for longitudinal movement and rotary movement in therupper portion of the headlight tester 5. A guide 2| carried by side Wall 5 ofthe headlight tester body also constitutes a bearing for the rod I 9,- Ythe ,rod being longitudinally and rotatably positioned Within the guide 2 I .Y Similarly arguide 22 ismounted upon the inner surface of Wall 5 and functions as a bearing member for the tube 20.-,Exteriorly of the headlight tester casing a `knurled disc 23 is positioned upon the project' ing end of tube 20, said disc'being immovably positioned-with respect tosaid tube. Upon the 'projecting end of the upper portion of rod I9 a l knob 24 is 'carried whereby the rod may be raised upwardly or moved downwardly or'rotated. Y

.TheA frame .18' comprises an opposed' Ypair of channel members 25 and end members 26 and 21.

The end'member 21 terminates in' a sleeve 28 (Figi 5) :which embracesan intermediate portion of rod I9 and is 'rigidly secured to Ysaid'rod by means of set screw 29. I

The upper channel member25carries. at one The arrangement is such'V that byzrotating the knurled disc 23 sheave 3 I. is'rotated and the cable 34 is'moved longitudinally in' one direction or the otherparallel'to thev channels25fln this fashion Photoelectric cell 32 is of conventional construction except as hereinafter noted and is of the type that generates its own voltage when a light impinges upon the activated surface thereof. The photoelectric cell is connected by suit-- able leads (not shown) to an electricmeter 35- which is positioned in housing 3,6 carried upon the upper wall 3 of the headlight tester. As a fea-- ture of our invention an opaque coating or layer photoelectric cell and a portion of said light, is f projected through lthe opening 39 through the cell and the concentric or coaxial opening in the tube 40, that is, fthe light will be channelled through the opening in thetube. the tube 40 is such as to dispose its rear open end adjacent the inner surface of the screen 9 whereeV by a minimum of dispersion occurs between the end of the tube andthe screen.. Consequently, when light impinges upon the exposed area 38 of the photoelectric cell a portion of said light will be projected through the opening`39and-will impinge upon the rear face of the screen 9.

In utilizing our invention, the' headlight tester is positioned in front of the headlight to be tested in the manner hereinbefore described. The `light from the headlight passes through the lens 1 and is focused at substantially the plane of the photoelectric cell. To locate the hot spot `ofthe light so focused the photoelectric cell 32 is moved trans;- versely and vertically by means 'of the knurleddise 23 and knob 24 `until a maximum reading is'obtained upon the meter 35. This indicates that the exposed circular area 38 of the photoelectric? cell 32 is substantially in lconcentric relationshipto the axis of the most intensive portion of thebearn.

. -Atfthis position the meter-35 Will ygive its. maxihigh'degree of accuracy.

mum deflection. Havingfthus appraised the hot spot of the beam electrically a small pencil of light is projected through the opening39 in the photoelectric cell and thispencil of light impinges upon the screen -9 in a more or less concentrated spot. Thus the electrically appraised hot spot can be visually located upon thecalibrated screen 9 with Referring particularly to Figs. 7 andf,` a'mdification of our inventionjis shown. In this form of our invention a headlight tester casing ,4I is contemplated, said casing being similar tothe the-photoelectric, cell 32 may. be carried'long'itudi- ,-henceithe photoelectric cell maybe positioned in ac'lli'll'ifiyof locations; transverse 4of the bodyfof nallyg-with respect'toJsaid channel members and Y the ,headlighttestenr In addition, ro'd I9 may-be vraised-or lowered by manipulating knob 24 to raise .or lower. the frameY I8 and accordingly-raise 'or .f 111e', I8 lI nayjbe swungV from its transverseposition within'thecasing toagposition WherelI-lit is parallel and adjacent to the wall 5.

casing hereinbefore described vexcept as indicated hereinafter.'` The casing 4I carriesfarframe 42 at its front end which is adapted to, support a lens 43 similar to lens 1, that is, both lenses are converging lenses. Unlike'l-fthe casing I f, the casing 4I is closed at its rear end as indicatedjat 44:.'V

Within the body of the casing andV intermediate the length of the casing aframe 45 is positioned, said frame 'being disposed at an angle of 45?'with respect to the longitudinalaxis of the casingf-A mirror 43 is supported upon the'frame 4,5,"fthe center of said mirror being disposed in substantial vaugmnent with the'opueai centerof melena-43.

The upperwall of casing 4I 'isv providedWij-jh.,v an

.openingv defined by aframe 41.l said frame-being combination a'frame, a converging lens carried upon said' frameV at one'xend thereof through which a light beam from a headlight to beftested is passed, a translucent screen carried upon said frame adjacent the opposite end thereof, with its center in alignment with theoptical axis of said lens .and withY its plane at; substantially right angles to the' axis oi'said light beam, alight sensitive device positioned adjacent said screenand between said lens and screen, means for moving said light sensitive device universally in a plane substantially parallel to the plane of said screen and in the path of said light beam from said lens, said light sensitive devieebeing of relatively large area provided with an aperture of relatively small area through which a portion of thek light beam of restricted cross section from said lens passes to said screen, and an electric meter connected to said light sensitive device.V responsive to that portion of Vthe light beam impinging upon the light. sensitive device.

v6. ,A headlight testing device comprising in combination a frame, a converging lens carried 'upon said frame at one end thereof lthrough which alight beam from a headlight under test ispassed, a translucent screen carried upon said frame with its plane Vat an angle to the plane of thelens, a light reective device carried by said frame at an angle to the plane -of the lens and the plane of said screen whereby the axis of the light beam from said lens'is reflected toward said screen, alight sensitive device positioned adjacent said screen, means for positioning said light sensitive device universallyin a plane at substantially right angles .to the reflected axis of the light beam :and inthe path ofthe light from said reflective device, said light sensitive devlcebeing of relatively large area and .being provided with an aperture of .relatively smallv area through which a portion ofthe light beam of restricted cross-section from said reflective device passes to said screen, and an electric meter connected toY Lsaid light sensitive deviceresponsve to that porsensitive device.

tion of the light beam impinging upon the'light 7. A. headlight testing device comprising in combination a frame, a converging lens carried upon said frame through which light from an adjacent headlight to be tested is passed, a translucent screen carried upon said frame in spaced relationship to said lens, alight sensitive device positioned between saidl lens'and said screen adjacent said screen, means for universally positioning said light sensitive device in a plane substantiallyvparallel to said screen and at substantially the axisof the beam of light from said lens, said light sensitive device being provided with a relatively restricted aperture, means positioned in said relatively restricted aperture and extending from said light sensitive device and terminating adjacent Asaid screen through Which a restricted pencil of a portion of the most intense light from said lens is channelled to impingement upon said screen in the form of an illuminated relatively restricted spot, and an electric meter connected to said light sensitive device responsive to that portion of the light impinging upon-the light sensitive device and surrounding said pencil of light. Y

HENRY E. HERMANN. RAYMOND S. KRAUSE.

' REFERENCES CITED The followingreferences are of record in the iile of this patent:

UNITED STATES PATENTS 702,213 Germany Feb. 1, 1941 

